Toggleable 'back' button in breadcrumbs navigation bar

[vincentsels]

When run as a mobile application on Apple devices instead of in a web browser, there is no dedicated 'back' button. How about integrating a toggleable 'back' button in the breadcrumbs navigation bar (so that it can be switched on only when deployed on Apple devices) ? It would just call history.back().

Something like this:

Or am I perhaps missing something?

If you agree, I'll send a pull request.